Ueki was the son of a middle-ranking samurai from Tosa. Inspired by Itagaki Taisuke, he became involved in the Jiyūtō. In 1875, he was thrown in jail under the Newspaper Act for writing an article critical of the government. Upon release he wrote an article "Freedom is worth purchasing with one's own blood". In 1881 he wrote A Private Draft of the Japanese Constitution, which gave provision for the overthrow of oppressive government.
In 1882 Ueki visited Fukushima in August and September at the invitation of the Fukushima Jiyūtō branch to help set up the Fukushima Jiyū Shimbun the local party newspaper, before returning to Tokyo to replace Baba Tatsui on the central party newspaper Jiyū Shimbun.
- Japan Since 1825 by Chushichi Tsuzuki, Oxford University Press, 2000